*{
  margin: 0;
  padding: 0;
  -webkit-box-sizing: border-box;
		  box-sizing: border-box;
}
/*====================================*/
body, html { font-size: 100%; 	padding: 0; margin: 0;}

body{
	background: #494A5F;
	color: #D5D6E2;
	font-weight: 500;
	font-size: 1.05em;
	font-family: "Microsoft YaHei","Segoe UI", "Lucida Grande", Helvetica, Arial,sans-serif;
}

.htmleaf-container{
	margin: 0 auto;
}
.htmleaf-header{
	padding: 1em 190px 1em;
	letter-spacing: -1px;
	text-align: center;
	background: #66677c;
}
.htmleaf-header h1 {
	color: #D5D6E2;
	font-weight: 600;
	font-size: 2em;
	line-height: 1;
	margin-bottom: 0;
}
/*====================================*/
.wrapper{
  width: 90%;
  margin: 0 auto;
  max-width: 80rem;
}

.cols{
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-wrap: wrap;
	  flex-wrap: wrap;
  -webkit-box-pack: center;
	  -ms-flex-pack: center;
		  justify-content: center;
}

.col{
  width: calc(25% - 2rem);
  margin: 1rem;
  cursor: pointer;
}

.container{
  -webkit-transform-style: preserve-3d;
		  transform-style: preserve-3d;
	-webkit-perspective: 1000px;
			perspective: 1000px;
}

.front,.back{
  background-size: cover;
	background-position: center;
	-webkit-transition: -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	-o-transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1), -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	-webkit-backface-visibility: hidden;
			backface-visibility: hidden;
	text-align: center;
	min-height: 280px;
	height: auto;
	border-radius: 10px;
	color: #fff;
	font-size: 1.5rem;
}

.back{
  background: #cedce7;
  background: -webkit-linear-gradient(45deg,  #cedce7 0%,#596a72 100%);
  background: -o-linear-gradient(45deg,  #cedce7 0%,#596a72 100%);
  background: linear-gradient(45deg,  #cedce7 0%,#596a72 100%);
}

.front:after{
	position: absolute;
	top: 0;
	left: 0;
	z-index: 1;
	width: 100%;
	height: 100%;
	content: '';
	display: block;
	opacity: .5;
	background-color: #000;
	-webkit-backface-visibility: hidden;
			backface-visibility: hidden;
	border-radius: 10px;
}
.container:hover .front, .container:hover .back{
	-webkit-transition: -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	-o-transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
	transition: transform .7s cubic-bezier(0.4, 0.2, 0.2, 1), -webkit-transform .7s cubic-bezier(0.4, 0.2, 0.2, 1);
}

.back{
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
}

.inner{
	-webkit-transform: translateY(-50%) translateZ(60px) scale(0.94);
			transform: translateY(-50%) translateZ(60px) scale(0.94);
	top: 50%;
	position: absolute;
	left: 0;
	width: 100%;
	padding: 2rem;
	-webkit-box-sizing: border-box;
			box-sizing: border-box;
	outline: 1px solid transparent;
	-webkit-perspective: inherit;
			perspective: inherit;
	z-index: 2;
}

.container .back{
	-webkit-transform: rotateY(180deg);
			transform: rotateY(180deg);
	-webkit-transform-style: preserve-3d;
			transform-style: preserve-3d;
}

.container .front{
	-webkit-transform: rotateY(0deg);
			transform: rotateY(0deg);
	-webkit-transform-style: preserve-3d;
			transform-style: preserve-3d;
}

.container:hover .back{
  -webkit-transform: rotateY(0deg);
		  transform: rotateY(0deg);
  -webkit-transform-style: preserve-3d;
		  transform-style: preserve-3d;
}

.container:hover .front{
  -webkit-transform: rotateY(-180deg);
		  transform: rotateY(-180deg);
  -webkit-transform-style: preserve-3d;
		  transform-style: preserve-3d;
}
@media screen and (max-width: 64rem){
  .col{
	width: calc(33.333333% - 2rem);
  }
}

@media screen and (max-width: 48rem){
  .col{
	width: calc(50% - 2rem);
  }
}

@media screen and (max-width: 32rem){
  .col{
	width: 100%;
	margin: 0 0 2rem 0;
  }
}